The invention relates to the facile achievement of length adjustment of an expansible chain of particular type.
Expansible chains are in common use as watch bands, identification bracelets or similar articles of jewelry. They must be fitted to the wrist of the user if they are to function satisfactorily, and the girth of the user's wrist varies widely from person to person. In addition, different individuals may have different desires with respect to snugness of the chain on the wrist. Further, the comfort attendant upon the use of a bracelet of given length by a particular person may vary from time to time--what is pleasantly snug in winter may be uncomfortably tight in summer, or the user's wrist may grow or shrink. For the retailer all of this presents a potential inventory problem--to stock a given bracelet style in many different sizes in order to accommodate all or most potential customers involves a significant investment and complete stocking of all sizes of all styles of bracelets is impractical, loss of potential sales may result, or else there is incentive to try to sell the customer a bracelet that is not of optimum length, possibly leading to customer dissatisfaction and loss of future sales.
Various constructions have been suggested in the past in an attempt to meet these problems. Most of them involve relatively complicated structures, such as the use of removable and replaceable push pins, which as a practical matter can be manipulated only by a skilled jeweler, and even then requiring an appreciable period of time in which to make the requisite adjustments. The problem is exacerbated by the fact that a given chain fitting in a store may involve several trials of different chain lengths before the final length is selected. Moreover, once the chain length is selected and the chain is purchased subsequent chain length adjustment by the purchaser is impractical.
Another approach adopted in connection with an expansible mesh chain formed of closely intertwined resilient wire lengths is to provide a housing into which an end of such a chain can be telescoped and providing that housing with a retaining member which, when the mesh chain is inserted into the housing to desired degree, may then be forced into the mesh chain to retain it is position. However, this has a serious disadvantage in that when the retainer member thus engages the chain it distorts the latter, thus making readjustment deleterious to the mesh.
Another approach has been to adjustably overlap two sections of the chains, sometimes within a housing and sometimes not, with means secured to one chain end which can engage the other chain end. When watch bands are involved housings have been provided at the ends of the watch with the entire bottom walls of the housing pivotal between chain engaging and chain releasing positions and having a part adapted to be received in gaps between adjacent links. The overlapping approach has the distinct disadvantage of thickening the band where the overlapping takes place, and the housing attached to the watch has the disadvantage of decreasing the effective length of the flexible chain, creating a visual discontinuity at the ends of the watch, where such a discontinuity would be most visible when on the wrist of the wearer. In addition, because the entire bottom wall of the housing is pivotable properly positioning the chain end within that housing is awkward and sometimes difficult.
One known type of expansible chain, disclosed in Reith U.S. Pat. No. 3,786,629 of Jan. 22, 1974 and entitled "Expansible Linkage For Use In Making A Watch Band Or Similar Article", has two layers of overlapping staggered links resiliently urged toward one another in the direction of shortening the chain length, with the outer layer of links having a greater dimension in the direction of the chain length than the links of the inner layer, so that when the chain is fully contracted the links of the outer layer engage one another and gaps remain between the links of the lower layer.
A prime object of the present invention is to provide means for adjusting the length of an expansible chain which is easy, rapid, may be readily accomplished by the jeweler or by the user, and does not adversely affect the expansible chain itself.
A further object of the present invention is to provide means for readily adjusting the length of an expansible chain comprising upper and lower layers of links wherein gaps normally exist between the links of the lower layer when the chain is in contracted condition which adjustment does not in any way adversely affect the chain structure itself or its appearance.
A further object of the present invention is to provide means for adjusting the length of an expansible chain over a range capable of accommodating all or almost all of the length potentially met with in the selling of chains to the general public.
To these ends a housing comprising a top wall, side walls and inwardly extending bottom wall sections is so shaped as to produce a recess into which one end of the chain of the above construction may be slid, the inwardly extending bottom wall sections supporting the chain when slid thereinto and, with the other walls, producing a cross-section for the recess which closely corresponds with the cross-section of the chain, the housing being provided with an articulately mounted retaining member vertically moveable between the inwardly extending bottom wall sections and having a toothlike part attached to be received in one of the gaps between the links of the lower layer of the chain, thereby to retain the chain end in said housing. The housing is symmetrically mounted so as to receive ends of chain lengths into opposite ends of the housing for length adjustability, the length of said housing for each chain end preferably being such as to receive at least three, and preferably at least four, sets of said upper and lower links beyond the toothlike part of the corresponding retainer member. As a result, merely by moving that retaining member between its chain engaging and chain releasing positions one may easily achieve extensive adjustment of the length of the chain that extends outside of the housing without distortion of or damage to the chain.